abstract architectural backdrop background barrier basic brick brick-wall bricks brickwork cement colored coloring colors coloured colouring colours constructed exterior external firm linear lines mortar perspective perspectives secure security smooth solid standard strength strong style surface surfaced surfaces texture textured textures traditional-brick-wall variation varied various wall walled wallpaper well-built curved curving rectangular rough-work off-white purple angle angles appearance architecture color colour discoloration paint rough smudged smudges uneven windows